Conserving Texas and Gulf Coast Flora with the CPC Plant Sponsorship Program
Mercer Botanic Gardens, a Harris County facility located in Humble, Texas, began endangered native plant conservation efforts around 1986 with the ex situ conservation (seed banking and propagation) of a local federally listed species, Texas prairie dawn, Hymenoxys texana (Asteraceae). Mercer became a Participating Institution of the Center for Plant Conservation (CPC) in 1989 under the guidance of Dr. Kathryn Kennedy, former US Fish and Wildlife Service (USFWS) botanist in Texas and former CPC President. At that time, San Antonio Botanical Garden (SABG) in south Texas served as the only CPC institution in the state. Once Mercer joined CPC, SABG – long-time partners of Mercer’s – transferred two federally listed East Texas species from their responsibility to Mercer’s. The Quaker Hill Foundation sponsored large-fruited sand verbena (Abronia macrocarpa) in 1990. Thanks to donations from Houston families (Dr. and Mrs. Sellers J. Thomas, Jr.; Mr. Frank A. Liddel, Jr.; Dr. and Mrs. Charles F. Squire) and the USFWS, white bladderpod (Physaria pallida) reached full sponsorship in 1999. Mercer’s research work continues in close partnership with our Texas CPC partners (SABG; Lady Bird Johnson Wildflower Center, University of Texas, Austin; and the Botanical Research Institute of Texas/Fort Worth Botanic Garden), as well as the out-of-state CPC network and governmental, academic, and non-profit partners.
I began my service as Mercer’s botanist and conservation manager in 2000. With CPC sponsorship stipends helping to fund expenses such as equipment, horticultural supplies, and travel costs for seed collections and field work, it made sense to me that sponsoring plants in the National Collection would help sustain Mercer’s native plant conservation program. Texas trailing phlox (Phlox nivalis spp. texensis), a beautiful, federally listed ‘Big Thicket’ Texas species, seemed like a perfect candidate for sponsorship. Mercer seed banks this species, assists reintroductions, and maintains educational displays in our Endangered Species and Native Plant Garden. Sponsorship was completed in 2003 by The River Oaks Garden Club; The Mercer Society’s ‘Mercer Memorial Trust Fund’; Mercer Volunteer Native Plant Team chairpersons, the late David C. Berkshire and Carol Kobb (in memory of her friend Millie Guadino); Mercer colleague and CPC ‘Conservation Champion’ Suzzanne Chapman in honor of her parents, Ann C. Baumer and Derek Chapman; and myself, in memory of my parents, Ruth L. and Werner G. Tiller.
As part of our service to Harris County, staff provide tours and lectures about the benefits of native plants and Mercer’s role in plant conservation. Our plant sponsorship donors include the garden clubs, members of the Texas Master Gardener, Naturalist, and Native Plant Society organizations that attend our lectures and tours. Donors include private individuals, nature-based organizations, volunteers, and sponsors recruited by the CPC National Office. Plant sponsorship donations often serve as memorials, and volunteers are among our most dedicated donors. The Gibson family—retired volunteers who worked alongside Suzzanne Chapman—completed full sponsorship of Texas windmill grass (Chloris texensis) in 2019 and Louisiana quillwort (Isoetes louisianensis) in 2020, and hope to complete the sponsorship of Scarlet catchfly, Silene subciliata (Caryophyllaceae) this year.
Our plant sponsorship efforts would not be possible without the support of Harris County staff and our non-profit arm, The Mercer Society. Harris County staff produced the educational brochure ‘Preserving Imperiled Plants’ and interpretive signage for Mercer’s Endangered Species and Native Plant Garden, and expanded our website to include a Plant Conservation section with links to CPC species profiles. These educational tools feature color images of National Collection species, acknowledge sponsorship donors, and help communicate the need to support rare and native plant conservation. Volunteer citizen scientists also provide integral support to Mercer’s native plant conservation and botany programs, including our curatorial, collections database, herbarium, library, garden signage and internship programs.
Mercer currently maintains 29 National Collection species with 10 fully and 5 partially sponsored species. Ongoing in situ projects include the management of naturally occurring populations of four rare saline prairie National Collection species at the Harris County Prairie Dawn Preserve. This tiny, less-than-4-acre preserve, located within Houston’s urban sprawl, was constructed in 2012-2013 and already shows promise. Texas prairie dawn and rare associate species are part of over 200 native species sheltered there. The preserve’s Texas windmill grass population currently represents the largest known population of this rare endemic.
This year, Mercer will propose additional vulnerable southeast Texas species for the National Collection. We thank the CPC Plant Sponsorship program for providing support to our efforts for the conservation of Texas and Gulf Coast flora. Through this funding, the CPC is helping Mercer fulfill its mission ‘to improve the quality of life and inspire the greater appreciation of the essential value and beauty of the plant world’ for the thousands of children and adults that tour our gardens and facilities and attend our programs.